dimmer switch

[svilen]

I have a problem with the dimmer switch for my halogen room lamp. It
has a ST BTA12-400C triac and works for 120v 60Hz 500W 4.3A.
I think it is the potentiometer that's giving problems, but it has no
markings so I can't understand what type it is or what's the
resistance. I tried to measure it, but it is not giving results I can
trust. I also measured the triac and it seems to be ok. If someone has
more experience with these things, please, let me know approximately
what values are used for the potentiometer in such kind of switches.
BTW, the producer is a company called Japen international, but I
couldn't find anything about it on the net. May be it doesn't exist
anymore, because the switch itself is prety old.

 

[John Popelish]

I have a problem with the dimmer switch for my halogen room lamp. It
has a ST BTA12-400C triac and works for 120v 60Hz 500W 4.3A.
I think it is the potentiometer that's giving problems, but it has no
markings so I can't understand what type it is or what's the
resistance. I tried to measure it, but it is not giving results I can
trust. I also measured the triac and it seems to be ok. If someone has
more experience with these things, please, let me know approximately
what values are used for the potentiometer in such kind of switches.
BTW, the producer is a company called Japen international, but I
couldn't find anything about it on the net. May be it doesn't exist
anymore, because the switch itself is prety old.

Pots usually go bad at the sliding contact point, but still have
pretty much the original resistance across the end contacts. I would
measure that resistance and try replacing the pot with one with a
similar overall resistance and see if it helped the symptoms.